Ashless dispersants comprising reaction product of acylating agent and aminoguanidine

ABSTRACT

Ashless dispersants are formed using polymers of propylene characterized in that they are liquid substantially linear polymers, they have stereo-irregularity in the polymer chain, at least 60 mol percent of the polymer has a terminal vinylidene group and, optionally, the polymer contains up to 25 mol percent of ethylene or a C 4  to C 10  monoolefin polymerized into the polymer chains.

This application is a divisional of application Ser. No. 077,724, filedJun. 16, 1993, now U.S. Pat. No. 5,433,875.

TECHNICAL FIELD

This invention relates to ashless dispersants for use in oleaginousmedia, notably oils of lubricating viscosity, andhydrocarbonaceous/fuels such as middle distillate fuels and heaverburner fuels.

BACKGROUND

Chemical additives for lubricating oils are used to control the physicaland chemical properties of lubricating oils. These additives are used tomodify oil viscosity and viscosity index, to make the oils moreresistant to oxidation, and to keep engines and other mechanicalequipment clean and protected against corrosion and wear. Water-solubleadditives are also commonly used in applications ranging from aqueoushydraulic fluids to household cleaners and cosmetics.

Hydrocarbon-based chemical additives are designed for specific functionsby choosing a hydrocarbon type and molecular weight range or molecularweight distribution to allow the additives to function in the fluid typeof interest. For instance, high molecular weight polymers can be used toincrease viscosity and viscosity index of mineral oils or syntheticoils. Water soluble polymers of polar compounds can be used to thickenwater, or even allow water to be pumped more easily. Polar head groupscan be designed to be attached to low or high molecular weighthydrocarbon tails to achieve detergency, dispersancy, antiwear oranticorrosion performance.

The hydrocarbon tail can be derived from natural fats or oils, or frompetroleum fractions. Synthetic tails can be assembled by thepolymerization of olefins or functionalized olefins or bypoly-condensation of difunctionalized olefins or saturated compounds.

The patent literature frequently describes the use of polymers ofolefins having 2 to 6 carbon atoms for use as oil-soluble tails suitablefor use in making oil additives. Indeed, some patents refer to use ofpolymers of even longer chain olefin monomers for this purpose.Extensive use is made of ethylene and butene or iso-butylene oligomersin forming oil additives. High molecular ethylene-propylene olefincopolymers are commonly used to increase the viscosity index oflubricating oils. Propylene trimer and tetramer have been used as lowmolecular weight tails, and technology to make branch C₂₀ to C₁₀₀polypropylene has been developed.

Despite the vast amount of work conducted heretofore, a need exists fornovel ashless dispersants that have enhanced thermal stability and/orthat can enable use of smaller amounts of viscosity index improvers informulating finished lubricants, giving a cost reduction. Because of therelatively high temperatures to which finished lubricating oils areexposed during actual service conditions, improved thermal stability isa desirable property in ashless dispersants. The advantage of having anashless dispersant which contributes viscosity increase to the lubricantand thus reduces the amount of viscosity index improver needed in thefinished oil is referred to, for example, in U.S. Pat. No. 4,234,435.

THE INVENTION

This invention is deemed to fulfill the foregoing need for providing andutilizing an ashless dispersant having in its chemical structure atleast one aliphatic substituent derived from a special type of polymer.The special polymers used in forming the dispersants are polymers ofpropylene characterized in that (a) they are liquid substantially linearpolymers, (b) they have stereo-irregularity in the polymer chain, (c) atleast sixty mol percent, preferably at least 75 percent and morepreferably at least 85 mol percent of the polymer has a terminaldivalent methylene group (═CH₂), and (d) optionally, they contain up to25 mol percent of ethylene or a C₄ to C₁₀ monoolefin polymerized intothe polymer chains. Preferred ashless dispersants are formed frompolypropylene homopolymer satisfying the foregoing requirements (a) (b)and (c).

As to type, the ashless dispersants of this invention can be succinicester-amide dispersants, succinimide dispersants, Mannich basedispersants, succinic amide-triazole dispersants, or succinic triazoledispersants. Process technology that can be adapted for producing thesevarious types of dispersants can be found in the literature. Forexample, an ene reaction (sometimes referred to as a thermal reaction)between the special polymer of propylene and maleic anhydride yields analkenyl-substituted succinic anhydride. This then can be converted intoan alkenyl succinic ester-amide using conditions such as are describedin U.S. Pat. Nos. 3,219,666; 3,282,959; 3,640,904; 4,426,305 or4,873,009; or into an alkenyl succinimide using conditions such asdescribed in U.S. Pat. Nos. 3,172,892; 3,219,666; 3,272,746; or4,234,435or into an alkenyl succinic triazole or alkenyl succinic amidetriazole dispersant (depending upon reaction proportions employed) usingconditions such as are described in U.S. Pat. Nos. 4,908,145 or5,080,815. By alkylating a phenolic compound with a special propylenepolymer as described above using a Lewis acid catalyst such as BF₃ orAlCl₃, and using reaction conditions such as are described in U.S. Pat.No. 3,736,353, an alkyl-substituted phenol is formed. Then by employingknown reaction condition such as are described in U.S. Pat. No.3,736,357, the alkylated phenol is reacted with an aldehyde such asacetalaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, furfurylaldehyde, etc., but preferably formaldehyde or a formaldehyde-producingreagent such as paraformaldehyde, formalin, etc,. and polyamine or apolyhydroxy-substituted amine, a Mannich base dispersant of thisinvention is formed.

The ashless dispersants of this invention can be post-treated (i.e.,reacted) with various post-treating agents such as are referred to inU.S. Pat. Nos. 4,234,435 or 5,137,908. Preferred post-treated ashlessdispersants of this invention are those which have been borated byreaction with a suitable boron-containing material, such as boric acidor other boron acids, boron oxide, boron trihalides, ammonium borate,super-borated ashless dispersants, etc. Generally speaking, the boratedashless dispersants will contain about 0.01 to about 1% by weight ofboron and preferably from about 0.05 to about 0.5 weight % of boronbased on the weight of the active dispersant (i.e., omitting fromconsideration the weight of any diluent or unreacted components that maybe present in the dispersant).

In general, the ashless dispersants producible pursuant to thisinvention are characterized by having enhanced thermal stability, byhaving relatively high useful viscosities when employed in lubricatingoil, and by possessing good dispersancy effectiveness. In addition,ashless dispersants of this invention can be produced having good shearstability. Moreover, it is possible to produce ashless dispersants ofthis invention having better handleability (e.g., lower viscosities atlow temperatures) than comparable dispersants made from polyisobutylene.

Accordingly, as compared to the same ashless dispersant made with apolypropylene of the same number average molecular weight but notmeeting the combined requirements of (a), (b), and (c) above, thedispersants of this invention tend to have higher thermal stabilities,higher useful viscosities, at least equivalent dispersancy, and equal orbetter shear stability. And as compared to the same ashless dispersantbut made with a polyisobutene of the same number average molecularweight, the dispersants of this invention tend to have lower viscositiesat low temperatures, and thus better handleability at low temperatures.

In contrast to stereo-regular polypropylene such as obtained withZiegler-Natta catalysts, the polymers of propylene used pursuant to thisinvention are formed by a route that gives a substantially linearproduct having a controlled amount of branching. The homopolymers ofthis type are preferred over the copolymers of this type as the formertend to form ashless dispersants that have the highest usefulviscosities and thus these dispersants offer the advantage of enablinguse of smaller amounts of VI improvers. Typically these homopolymerscontain an average in the range of about 15 to about 250 propylenemoieties in the polymer chains. U.S. Pat. No. 4,814,540 describes onemethod which may be used to form such polymers.

Polyamines (including polyether polyamines) and polyhydroxy amines thatcan be used in forming dispersants of this invention have at least oneprimary or secondary amino group in the molecule. Amines of this typeand also polyols that can be used in forming ester-amide dispersants ofthis invention are extensively described in the patent literature, suchas, for example U.S. Pat. Nos. 4,234,435, 4,873,009 and 5,137,980.

Accordingly, among the embodiments of this invention is an ashlessdispersant having in its chemical structure at least one aliphatichydrocarbyl substituent derived from a liquid, substantially linearpolymer of propylene, said polymer having stereo-irregularity andoptionally containing up to 25 mol percent of ethylene or C₄ to C₁₀monoolefin polymerized into the polymer chain, at least 60 mol percentof said polymer having a terminal vinylidene group, said dispersantbeing a Mannich base formed from (i) a phenol having said aliphaticsubstituent thereon, (ii) an aldehyde, and (iii) an amine selected frompolyamines and polyhydroxy amines. In these dispersants the preferredaldehyde is formaldehyde or a formaldehyde-forming reagent and thepreferred amine is a polyamine, most preferably an ethylene polyaminesuch as diethylene triamine, triethylene tetramine, tetraethylenepentamine, or pentaethylene hexamine.

Another embodiment is an ashless dispersant having in its chemicalstructure at least one aliphatic hydrocarbyl substituent derived from aliquid, substantially linear polymer of propylene, said polymer havingstereo-irregularity and optionally containing up to 25 mol percent ofethylene or C₄ or C₁₀ monoolefin polymerized into the polymer chain, atleast 60 mol percent of said polymer having a terminal vinylidene group,said dispersant being a succinic ester-amide formed from (i) an alkenylsuccinic acylating agent having said substituent thereon and (ii) anN-substituted poly(hydroxyalkyl) amine or a combination of a polyamineand a polyol, which polyamine and polyol are reacted with said acylatingagent concurrently or sequentially in any order. Of these dispersants,it is preferable to react the acylating agent with an alkylene diaminehaving 4 to 12 carbon atoms in the molecule and at least about 2.5hydroxyalkyl groups per molecule in accordance with the teachings ofU.S. Pat. No. 4,873,009. Most preferred dispersants of this type areformed by reacting the acylating agent with hexamethylene diamine havingabout 3 hydroxyalkyl groups per molecule.

Still another embodiment of this invention is an ashless dispersanthaving in its chemical structure at least one aliphatic hydrocarbylsubstituent derived from a liquid, substantially linear polymer ofpropylene, said polymer having stereo-irregularity and optionallycontaining up to 25 mol percent of ethylene or C₄ to C₁₀ monoolefinpolymerized into the polymer chain, at least 60 mol percent of saidpolymer having a terminal vinylidene group, said dispersant being asuccinimide formed from (i) an alkenyl succinic acylating agent havingsaid substituent thereon and (ii) a polyamine having at least oneprimary amino group in the molecule. Preferably the polyamine used is atleast one cyclic or acyclic ethylene polyamine having an average of from3 to 6 nitrogen atoms per molecule. It is even more preferably to employethylene polyamines selected from diethylene triamine, triethylenetetramine, tetraethylene pentamine, and pentaethylene hexamine.

A further embodiment of this invention is an ashless dispersant havingin its chemical structure at least one aliphatic hydrocarbyl substituentderived from a liquid, substantially linear polymer of propylene, saidpolymer having stereo-irregularity and optionally containing up to 25mol percent of ethylene or C₄ to C₁₀ monoolefin polymerized into thepolymer chain, at least 60 mol percent of said polymer having a terminalvinylidene group, said dispersant being a product formed by reacting (i)an alkenyl succinic acylating agent having said substituent thereon and(ii) a basic salt of aminoguanidine wherein the molar ratio of saidaminoguanidine to said acylating agent is in the range of about 1.4:1 toabout 2.2:1 such that the product obtained upon reaction thereofexhibits a dominant infrared peak at 1640 cm⁻¹. Preferably, the basicsalt of aminoguanidine used is aminoguanidine bicarbonate.

A still further embodiment of this invention is an ashless dispersanthaving in its chemical structure at least one aliphatic hydrocarbylsubstituent derived from a liquid, substantially linear polymer ofpropylene, said polymer having stereo-irregularity and optionallycontaining up to 25 mol percent of ethylene or C₄ to C₁₀ monoolefinpolymerized into the polymer chain, at least 60 mol percent of saidpolymer having a terminal vinylidene group, said dispersant being aproduct formed by reacting (i) an alkenyl succinic acylating agenthaving said substituent thereon and (ii) a basic salt of aminoguanidinewherein the molar ratio of said aminoguanidine to said acylating agentis in the range of about 0.4:1 to about 1.3:1. Preferably, theseproducts exhibit an infrared spectrum having peaks in the region ofabout 1580 and about 1690 cm⁻¹. Another preferred product of this typeyields an infrared spectrum having a peak in the region of about 1720cm⁻¹.

Yet another embodiment of this invention is an ashless dispersant havingin its chemical structure at least one aliphatic hydrocarbyl substituentderived from a liquid, substantially linear polymer of propylene, saidpolymer having stereo-irregularity and optionally containing up to 25mol percent of ethylene or C₄ to C₁₀ monoolefin polymerized into thepolymer chain, at least 60 mol percent of said polymer having a terminalvinylidene group, said dispersant being further characterized by havinga higher thermal stability than an identical ashless dispersant formedfrom a stereo-regular polymer of propylene in which at least 60 molpercent of the polymer has an internal olefinic double bond.

Preferably, the substantially linear polymer of propylene used in makingall of the foregoing dispersants is a homopolymer.

Another embodiment of this invention comprises the use of from 0.5 to20% by weight, and preferably from 3 to 15% by weight, of an ashlessdispersant of this invention in an oil of lubricating viscosity in orderto provide a viscosity increase to said oil, and thereby to enable areduction in the amount of viscosity index improver required to achievea target viscosity.

The use of from 0.5 to 20% by weight, and preferably from 3 to 15% byweight, of an ashless dispersant of this invention in an oil oflubricating viscosity subjected to an elevated temperature (e.g., atleast 200° C. and preferably at least 250° C. during use to providedispersancy without substantial thermal degradation of the dispersant,is another embodiment of this invention.

A still further embodiment of this invention is the use in forming anashless dispersant of a liquid, substantially linear polymer ofpropylene to create a substituent of said ashless dispersant thatrenders the dispersant capable of providing a beneficial viscosityincrease in an oil of lubricating viscosity when the dispersant isdissolved therein at a concentration within the range of 0.5 to 20% byweight, said polymer having stereo-irregularity and optionallycontaining up to 25 mol percent of ethylene or C₄ to C₁₀ monoolefinpolymerized into the polymer chain, at least 60 mol percent of saidpolymer having a terminal vinylidene group.

Preferred dispersants of this invention are those that have the abilityto increase the 100° C. kinematic viscosity of an additive-free basemineral oil that has a 100° C. kinematic viscosity in the range of 5.0to 5.5 cSt by at least 50%, more preferably by at least 60%, and mostpreferably by at least 70%, when dissolved therein at a concentration of3.5 wt % based on the total weight of the resulting solution.

These and other embodiments will be apparent from a consideration ofthis specification and the appended claims.

The following examples illustrate the practice and advantages achievableby the practice of this invention. These examples are not intended tolimit, do not limit, and should not be construed as limiting the genericscope of this invention.

EXAMPLE 1

A mixture of 24.6 g (0.02 mol) of a liquid polypropylene and 5.8 g (0.06mol) of phenol together with 3.1% of boron trifluoride complexed withphenol was stirred for 2.5 hours at 49° C. This polypropylene, preparedby Amoco Chemical Company, was substantially linear and hadstereo-irregularity in the polymer chains. Its number average molecularweight by gel permeation chromatography was 1230, and 95% of the polymerwas unsaturated with more than 90% of the chains terminated with adivalent methylene group (═CH₂) as part of a vinylidene structure(>C═CH₂). At the end of the 2.5 hour period, the catalyst wasneutralized with gaseous ammonia, and the excess phenol was strippedwith nitrogen to 177° C. yielding 26 g of alkylated phenol product. Theproduct was then filtered yielding 22 g of filtered alkylated phenolproduct.

EXAMPLE 2

To a mixture of 17.7 g (0.01 mol) of the product of Example 1, 4 mLxylene, 1.16 g (0.01 mol) of diethylene triamine, and 0.31 g (0.001 mol)of oleic acid, at 88° C. was added 3.02 g (0.037 mol) of 37% formalin.After 1 hour at 92° C., the mixture was warmed to 166° C. and stirredfor 3 hours to give 17.7 g of Mannich base dispersant of this invention.

EXAMPLE 3

A mixture of 40 g (0.013 mol) of a liquid polypropylene and 3.9 g (0.04mol) of phenol/borontrifluoride complex was reacted for 3 hours at 49°C. This polypropylene, also supplied by Amoco Chemical Company, had thesame characteristics as that used in Example 1 above, except that thepolymer was more viscous (1047 cSt at 100° C.; 117,715 cSt at 40° C.),had a molecular weight as determined by vapor phase osmometry of 2225and was 91% unsaturated. It had a viscosity index of 126. At the end ofthe 3-hour reaction period, the product was neutralized with gaseousammonia, and the product was stripped to 177° C. to give 40.5 g ofalkylated phenol product.

EXAMPLE 4

At 88° C., 1.24 g (0.015 mol) of formalin was added to a mixture of 32 g(0.008 mol) of the alkylated phenol of Example 3, 1.44 g (0.008 mol) oftetraethylene pentamine, 0.85 g (0.003 mol) of oleic acid, and 14 g of95 Neutral Mid-continent base oil. After 1 hour at 116° C., the mixturewas warmed to 155° C., and 1.86 g (0.023 mol) of formalin was added.After 2 hours at 155° C., the product (47.5 g) was filtered. The Mannichbase dispersant of this invention so formed had a TBN of 16 by ASTMD2896.

EXAMPLE 5

The procedure of Example 3 was repeated except that the alkylation wasconducted in 40 mL of heptane.

EXAMPLE 6

The procedure of Example 4 was repeated but with the addition to thereaction system of 25 mL of heptane as a diluent, and using 30.6 g(0.009 mol) of the product of Example 5 that had been stripped to 177°C. with nitrogen. The Mannich base product of this invention formed inthis manner was produced in a yield of 45.5 g, and it had a TBN of 22.

COMPARATIVE EXAMPLE A

A mixture of 24.6 g (0.02 mol) of Ultravis 30 polybutene supplied byBASF and 5.8 g (0.06 mol) of phenol/borontrifluoride complex was stirredfor 2.5 hours at 49° C. This polybutene had a number average molecularweight of 1230, contained more than 95% unsaturation, and had more than70% vinylidene end groups. After neutralization with ammonia, theproduct was stripped to 177° C. to yield 25.6 g of a long-chainalkylphenol formed from polybutene.

COMPARATIVE EXAMPLE B

At 88° C., 1.36 g (0.034 mol) of formalin was added to a solution of14.6 g (0.01 mol) of the product of Comparative Example A, 1.05 g (0.01mol) of diethylene triamine, 0.29 g (0.001 mol) of oleic acid, and 4 mLof xylene. After 1 hour at 92° C., the mixture was stripped to 166° C.and stirred for 3 hours to yield a Mannich base dispersant having along-chain derived from polybutene.

COMPARATIVE EXAMPLE C

Polybutene having a number average molecular weight of 2100, sold byAmoco Chemical Company as H-1500 polybutene, was reacted with phenol inthe presence of boron-trifluoride complex to give an alkylated phenolusing reacting conditions described in U.S. Pat. No. 3,736,357.

COMPARATIVE EXAMPLE D

A Mannich base dispersant was prepared by the reaction of the alkylatedphenol of Comparative Example C with tetraethylene pentamine andformaldehyde as described in U.S. Pat. No. 3,736,357. The product wasthen borated to yield a boronated Mannich base dispersant having along-chain derived from polyisobutylene.

COMPARATIVE EXAMPLE E

The procedure of Comparative Example D was repeated except that E-100polyethylene polyamine bottoms from Dow Chemical Company was used as theamine source, and the Mannich base dispersant was not subjected toboration.

The products produced as in Examples 4, 6, and Comparative Example Dwere blended at 8% by weight into a Mid-Continent base oil having a 100°C. viscosity of 5.45 cSt. The blend with the ashless dispersant ofExample 4 had a viscosity of 9.26 cSt at 100° C., and the blend with theashless dispersant of Example 6 gave a viscosity of 8.95 cSt at 100° C.,while the dispersant of Comparative Example D gave a viscosity of 7.25cSt at 100° C. These respective dispersants were of nearly equalactivities and were derived from polymers of nearly equal molecularweights. That is, the dispersants of Examples 4 and 6 had a content ofactive dispersant of 42 weight % whereas the dispersant of ComparativeExample D had a content of active dispersant of 40 weight %. And it willbe noted that the Mannich dispersants of this invention (Examples 4 and6) gave higher 100° C. viscosities than the dispersant of ComparativeExample D by virtue of the advantageous special structure of thepolypropylene used in forming the dispersants of Examples 4 and 6.

The products made as in Examples 4, 6 and Comparative Example D werethen blended into a 5W-30 motor oil formulated with metal-containingphenates and sulfonates, zinc dithiophosphate wear inhibitors,sulfur-containing antioxidant and a viscosity index improver supplied byShell Chemical Company (Shellvis 200C). With 8% of the dispersant ofComparative Example D, 6.5% of the viscosity index improver wasnecessary to meet a viscosity target of 11.2 cSt at 100° C. On the otherhand, with the product of Example 6 at 8% concentration in the finishedoil, and only 5.5% by weight of the same viscosity index improver, theoil viscosity was well above the 11.2 cSt target--this oil had aviscosity of 13.4 cSt at 100° C. These results thus show the ability ofthe dispersants of this invention to contribute significant viscosityindex credit to the oil and thereby enable reduction of the amount ofthe conventional viscosity index improver needed to achieve the desiredviscosity target. Reducing the amount of viscosity index improver in amotor oil can thus offer both cost and engine cleanliness advantages.

The ability of the dispersants of this invention to disperse enginesludge was measured in a bench test where 5 to 6% of a test dispersantis added to a severe used oil from a Sequence VE engine test. This usedoil is viscous and serves as a source of engine sludge. The dispersantand used VE oil are heated, shaken, and stored overnight at 149° C.After again shaking, seven drops of the oil are dropped onto Whatman No.3031 915 blotter paper. After 16 hours, the diameters of the inner ringof dispersed sludge and outer oil ring are measured. The percent spotdispersancy is the diameter of the inner ring, divided by the diameterof the outer ring, times 100. Without dispersant, values of 36 to 38%are obtained. Values above 70% with 5 or 6% added dispersant areindicative of good dispersancy. This test procedure is described inExample 1 of U.S. Pat. No. 4,908,145.

The product of Comparative Example D added at 6 and 5% gave percent spotdispersancies of 83 and 79%, respectively. This product exhibitsexcellent properties in the Sequence VE test and the Sequence IIIE test.It also exhibits excellent diesel engine performance. The productsformed as in Example 6 at 6 and 5% gave percent spot dispersancies of 86and 81% showing that excellent dispersancy is likewise achieved by thisdispersant of this invention. The product of Example 4 exhibited percentspot dispersancies of 76 and 63 at 6 and 5respectively. Thus it alsoexhibited good dispersancy, albeit somewhat less than that of theproduct of Example 6.

The excellent thermal stability achievable by the practice of thisinvention was shown by the use of a hot tube test using an oilformulated for use in locomotive engines as described in U.S. Pat. No.4,948,523. In this test, the formulated oil is pumped through asmall-bore glass tube heated at 296° C. over a 16-hour period. Thedeposits are visually rated on a scale of 0 to 10, with 10 being clean.The dispersant of this invention produced as in Example 6 gave ratingsof 7.5 and 8.0 in repeat tests. In contrast, the ashless dispersantproduced as in Comparative Example E gave ratings of 4.0 and 0.5.

In addition to the foregoing advantages achievable by the practice ofthis invention is the fact that propylene has been historically lessexpensive that isobutylene or even a mixed stream of butenes. This costdifferential may increase in the future as the use of isobutylene andother butenes is increased to make oxygenated blending agents, such asmethyl tert-butyl ether for use in gasoline and other fuels.

In formulating finished lubricating oils containing one or more of theashless dispersants of this invention, various other additive componentscan be utilized. These include low-base and overbased alkali and/oralkaline earth metal detergents, such as the sulfonates, sulfurizedphenates and salicylates of lithium, sodium, potassium, calcium and/ormagnesium, and the alkaline earth metal calixerates (note U.S. Pat. Nos.5,114,601 and 5,205,946); antiwear and/or extreme pressure agents suchas metal salts of dihydrocarbyl dithiophosphoric acids (e.g., zinc,copper or molybdenum dialkyldithiophosphates); oxidation inhibitors suchas hindered phenolic antioxidants, aromatic amine antioxidants,sulfur-containing antioxidants, and copper-containing antioxidants;supplementary dispersants such as succinimide dispersants, succinicester-amide dispersants, and Mannich base dispersants; friction reducingand/or fuel economy improving additives such as glycerol monooleate,pentaerythritol monooleate, long chain acid esters of glycols,sulfurized olefins, sulfurized unsaturated fatty acids and sulfurizedunsaturated fatty acid esters; rust and corrosion inhibitors; foaminhibitors; viscosity index improvers; polymeric dispersant-viscosityindex improvers; demulsifying agents; and the like. Such additives canbe employed in the base oil at their customary use concentrations, whichare known to those skilled in the art and reported in numerous patentdisclosures. For further details concerning such additives, one mayrefer for example to U.S. Pat. Nos. 4,664,822; 4,908,145; 5,080,815 and5,137,980.

The base oils used in formulating finished lubricants containing theashless dispersants of this invention can be derived from petroleum (ortar sands, coal, shale, etc.). Likewise, the base oils can be or includenatural oils of suitable viscosities such as rapeseed oil, etc., andsynthetic oils such as hydrogenated polyolefin oils; poly-α-olefins(e.g., hydrogenated or unhydrogenated α-olefin oligomers such ashydrogenated poly-1-decene); alkyl esters of dicarboxylic acids; complexesters of dicarboxylic acid, polyglycol and alcohol; alkyl esters ofcarbonic or phosphoric acids; polysilicones; fluorohydrocarbon oils; andthe like. Mixtures of mineral, natural and/or synthetic oils in anysuitable proportions are also useable. The term "base oil" for thisdisclosure includes all the foregoing. In most cases the base oil ispreferably a petroleum-derived mineral oil of the types conventionallyused in forming passenger car or heavy duty diesel engine oils. The factthat the base oils used in the compositions of this invention may becomposed of (i) one or more mineral oils, (ii) one or more syntheticoils, (iii) one or more natural oils, or (iv) a blend of (i) and (ii),or (i) and (iii), or (ii) and (iii), or (i), (ii) and (iii) does notmean that these various types of oils are necessarily equivalents ofeach other. Certain types of base oils may be used for the specificproperties they possess such as biodegradability, high temperaturestability, or non-flammability. In other compositions, other types ofbase oils may be preferred for reasons of availability or low cost.Thus, the skilled artisan will recognize that while the various types ofbase oils discussed above may be used in the compositions of thisinvention, they are not necessarily equivalents of each other in everyinstance.

The ashless dispersants of this invention can be blended into oils oflubricating viscosity separately and apart from other additivecomponents. Preferably however, the dispersants are formulated into anadditive concentrate or "package" which is then used in formulating thefinished lubrication compositions. The package will usually contain upto 50 wt % of diluent with the balance being the active additivecomponents, namely, at least one dispersant of this invention andoptionally, but preferably, one or more other additive components, suchas those referred to above and/or in various patents cited herein. From5 to 60 wt % of the concentrate can be one ore more dispersants of thisinvention. This invention also provides a composition which consists of1 to 99 wt % of an active dispersant of this invention and from 99 to 1wt % of diluent oil. Other additives, including diluents that may beassociated therewith, can be blended into such compositions to formadditive packages of this invention.

The dispersants of this invention can also be used as additives inhydrocarbonaceous fuels such as gasoline, diesel fuel, gas oils, jetfuels, cycle oils, burner fuels, bunker fuels, and the like. Amountswithin the range of 0.5 to 10% by weight will usually be employed,although departures from this range can be made.

Lower molecular weight versions of the polymers of propylene referred tohereinabove can be used in alkylation of aromatic hydrocarbons. Thesealkylated materials (e.g., alkylated benzene, alkylated toluene,alkylated xylenes, etc.) can then be sulfonated and overbased to formhighly useful alkali or alkaline earth metal containing detergents andrust inhibitors. Alternatively, the polymers of propylene can be used toalkylate hydroxy-substituted aromatic hydrocarbons, which can besulfurized and neutralized or overbased to form metal-containing phenatedetergents.

Except as referred to in the examples, all percentages of thedispersants of this invention are in terms of the weight of activedispersant in relation to the total weight of the overall compositionunder discussion.

The complete disclosure of each U.S. Patent cited anywhere hereinaboveis incorporated herein by reference as if fully set forth in thisspecification.

This invention is susceptible to considerable variation in its practice.Accordingly, this invention is not intended to be limited by thisspecific exemplifications set forth hereinabove. Rather, this inventionis intended to embrace the subject matter within the spirit and scope ofthe appended claims and the permissible equivalents thereof.

What is claimed:
 1. An ashless dispersant having in its chemicalstructure at least one aliphatic hydrocarbyl substituent derived from aliquid, linear polymer of propylene, said polymer havingstereo-irregularity and optionally containing up to 25 mol percent ofethylene or C₄ to C₁₀ monoolefin polymerized into the polymer chain, atleast 60 mol percent of said polymer having a terminal vinylidene group,said dispersant being a product formed by reacting (i) an alkenylsuccinic acylating agent having said substituent thereon and (ii) abasic salt of aminoguanidine wherein the molar ratio of saidaminoguanidine to said acylating agent is in the range of about 1.4:1 toabout 2.2:1 such that the product obtained upon reaction thereofexhibits a dominant infrared peak at 1640 cm⁻¹.
 2. An ashless dispersantaccording to claim 1 wherein said linear polymer of propylene is apropylene homopolymer.
 3. An ashless dispersant according to claim 1wherein said basic salt of aminoguanidine is aminoguanidine bicarbonate.4. A lubricating oil composition containing from 0.5 to 60% by weight ofan ashless dispersant of claim
 1. 5. An ashless dispersant having in itschemical structure at least one aliphatic hydrocarbyl substituentderived from a liquid, linear polymer of propylene, said polymer havingstereo-irregularity and optionally containing up to 25 mol percent ofethylene or C₄ to C₁₀ monoolefin polymerized into the polymer chain, atleast 60 mol percent of said polymer having a terminal vinylidene group,said dispersant being a product formed by reacting (i) an alkenylsuccinic acylating agent having said substituent thereon and (ii) abasic salt of aminoguanidine wherein the molar ratio of saidaminoguanidine to said acylating agent is in the range of about 0.4:1 toabout 1.3:1.
 6. An ashless dispersant according to claim 5 wherein saidproduct exhibits an infrared spectrum having peaks in the region ofabout 1580 and about 1690 cm⁻¹.
 7. An ashless dispersant according toclaim 5 wherein said product exhibits an infrared spectrum having a peakin the region of about 1720 cm⁻¹.
 8. An ashless dispersant according toclaim 5 wherein said linear polymer of propylene is a propylenehomopolymer.
 9. An ashless dispersant according to claim 5 wherein saidbasic salt of aminoguanidine is aminoguanidine bicarbonate.
 10. Alubricating oil composition containing from 0.5 to 60% by weight of anashless dispersant of claim 5.